PsycuHeE, 1910. Vou. XVII, Pirate f2. 










FORBES--AQUATIC CATERPILLARS. 
Fig. 4. Tracheal gills of penultimate stage of N. maculalis, photomicrograph. 
Fig. 5. Penultimate stage of N. maculalis seen by transmitted light; alive but 
stupefied with chloratone. 
Fig. 6. Cocoon of N. icciusalis on submerged stem of Potamogeton; enlarged 
about two times. 
